Current wireless handheld mobile communication devices perform a variety of functions to enable mobile users to stay current with information and communications, such as e-mail, corporate data and organizer information while they are away from their desks. A wireless connection to a server allows a mobile communication device to receive updates to previously received information and communications. The handheld devices optimally are lightweight, compact and have long battery life. In order to conserve power consumption of the devices, “sleep” modes are provided which selectively either slow down the clocking rate of the components, selectively de-activate components, or both. However, when in a sleep mode, a re-activation signal can be generated after a certain event (e.g. movement of the device, receipt of a message, etc.) which is used to re-activate the device. Such events can be detected by electronic sensors in the device. However, such sensors need to be continually powered, thereby draining power from the battery.
Processing a re-activation signal also has issues. Prior art devices have fed the re-activation signal to an interrupt request (IRQ) line of a microprocessor in the device. A power-up routine operating on the microprocessor monitors for the activation of the IRQ line and when it is received, the routine causes the microprocessor to power up. The technique can be inefficient for power management, as once the IRQ line is activated, the microprocessor is fully re-activated, thereby draining a significant amount of power. False positive IRQ signals will cause unnecessary re-activations of the microprocessor.
There is a need for a system and method which addresses deficiencies in the prior art.